Setting providers define a mechanism for storing configuration data used in the application settings architecture. The .NET Framework contains a single default settings provider, LocalFileSettingsProvider, which stores configuration data to the local file system. A application settings property or group of properties is associated to a specific settings provider through the use of the SettingsProviderAttribute.

Typically, the client program does not does not explicitly access this class; rather, the application settings architecture automatically invokes the appropriate settings provider when its services are required. For example, many of the members of ApplicationSettingsBase delegate their work to the associated settings provider.

LocalFileSettingsProvider persists settings to configuration files that have the extension .config. The contents of configuration files are structured as XML documents. Depending on whether the setting is scoped at either the application-level or user-level, the configuration data is stored as elements within an <applicationSettings> or a <userSettings> section group, respectively. Each of these section groups is represented by a corresponding AppSettingsSection or ClientSettingsSection, respectively. Each section object is owned and administered by a configuration section handler, which is an object of type IConfigurationSectionHandler.

Application-scoped settings and the default user-scoped settings are stored in a file named application.exe.config, which is created in the same directory as the executable file. Application configuration settings are read-only. Specific user data is stored in a file named username.config, stored under the user's home directory. If roaming profiles are enabled, two versions of the user configuration file could exist. In such a case, the entries in the roaming version take precedence over duplicated entries in the local user configuration file.